loophole

[…] and having a fair loophole, as it were, from a broken hole in the tree, he took a sure aim, without being seen, waiting till they were within about thirty yards of the tree, so that he could not miss.

Coupling the poor girl's intelligence with my previous knowledge, and the result of our good friend's inquiries on the spot, I left him no loophole of escape, and laid bare the whole villany which by these lights became plain as day.